Acta Dermato-Venereologica 98-4CompleteContent

396 CLINICAL REPORT Epidemiology and Medication Trends in Patients with Psoriasis: A Nationwide Population-based Cohort Study from Korea Ju Hee HAN 1 , Ji Hyun LEE 1 , Kyung Do HAN 2 , Hyun-Min SEO 1 , Chul Hwan BANG 1 , Young Min PARK 1 , Jun Young LEE 1 and Yong Gyu PARK 2 Department of Dermatology, Seoul St. Mary’s Hospital, and 2 Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea 1 This study investigated the prevalence of psoriasis and trends in prescription of medications for patients with psoriasis using the Korean National Health Insurance Claims Database from 2006 to 2015. The prevalence of psoriasis and psoriatic arthritis per 10,000 people increased from 47.4 to 61.5 and from 0.04 to 0.23 re- spectively. The prescription of topical agents was a mean of 73.3%. For systemic agents, prescription of acitretin decreased from 74.8 to 44.5%, methotrexate showed a fluctuation, with a mean of 14.9% and cy- closporine increased from 9.0 to 41.2%. The prescrip- tion of biological agents increased sharply from 18 to 1,127 patients. Use of ustekinumab increased from 4.1 to 82.4%; use of infliximab decreased from 20.7 to 6.7% and etanercept decreased from 100 to 6.1%. This study showed an increasing trend in the preva- lence of psoriasis. We also reported a rapid increase in the use of biologics in recent years. Key words: epidemiology; psoriasis; psoriatic arthritis; preva lence; medication. Accepted Dec 20, 2017; Epub ahead of print Dec 21, 2017 Acta Derm Venereol 2018; 98: 396–400. Corr: Ji Hyun LEE, Department of Dermatology, College of Medicine, The Catholic University of Korea, Seoul 137-040, Korea. E-mail: yiji1@han mail.net P soriasis is a T-helper-1 and -17 cell-mediated, chro- nic, inflammatory skin disease affecting approxima- tely 1–3% of the general population (1, 2). The public health burden of psoriasis increases with rising preva- lence. Psoriasis can involve skin, nails, and joints and be associated with a variety of systemic comorbidities such as cardiovascular disorders, stroke, hypertension, dyslipidemia, diabetes, metabolic syndromes and obesity (1, 3). The estimated prevalence of psoriatic arthritis (PsA) in psoriasis patients was 13.8% in the UK when using the ClASsification criteria for Psoriatic ARthritis (CASPAR) (4). Patients with psoriasis are increasingly burdened with comorbidities. In a systematic review, in 2013, the cost of psoriasis was estimated to be more than $121 billion (5). Topical agents are generally the fist-line treatment for psoriasis, especially for mild disease, followed by phototherapy and DMARDs (disease-modifying antir- heumatic drugs). In widespread disease, topical agents in combination with phototherapy or DMARDs could doi: 10.2340/00015555-2877 Acta Derm Venereol 2018; 98: 396–400 be considered. For patients who do not respond to these therapies, or certain patients who have PsA or nail invol- vement, biologic agent are recommended (6–8). This study used the National Health Insurance System (NHIS) Claims Database of Korea in a nationwide study. In 1989, universal health coverage was achieved by the government that provides coverage for nearly 100% of the Korean population (9). This study examined the prevalence of psoriasis and the use of antipsoriatic medi- cations in patients with psoriasis from 2006 to 2015. This study has a limitation that the prevalence of psoriasis might be underestimated. MATERIALS AND METHODS Data source This was a nationwide, population-based study. Data were from the NHIS claims database, which contains all billing claims provided by the NHIS program and the medical aid system from January 2006 through December 2015. The NHIS system is a mandatory universal health insurance program that contains com- prehensive health-related information on the Korean population that is composed of all claims data such as drug prescriptions, International Classification of Disease (ICD) codes, and details about treatment (10). The Korean NHIS database represents the entire population and covers nearly 100% of the Korean popula- tion (from 48,341,311 individuals in 2006 to 51,574,044 in 2015) (11). In this study, age, sex and diagnostic codes for psoriasis and PsA based on the International Classification of Diseases, 10 th revision (ICD-10) were retrieved with detailed information about prescriptions. This study was approved by the Ethics Committee of Seoul St. Mary’s Hospital, the Catholic University of Korea (KC16EISE0922) and was conducted according to the principles of the Declaration of Helsinki. Study population The study population consisted of patients who visited clinics or hospitals with an ICD-10 code of psoriasis (ICD-10 L40) and PsA (ICD-10 M073) more than once in a given year from January 2006 through December 2015. Prevalence was analyzed by classifying patients into 10 age groups: 0–9 years, 10–19 years, 20–29 years, 30–39 years, 40–49 years, 50–59 years, 60–69 years, 70–79 years, 80–89 years and > 90 years. The patients were classified into mo- derate to severe psoriasis who had received any systemic agent and mild psoriasis who had not received any systemic agents. Statistical analyses We analyzed prevalence of psoriasis by age, categorized into 10-year age groups. Prevalence of psoriasis from 2006 to 2015 was reported by level of disease severity. Prevalence in 2015 was This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica.

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